Differentiation capacity of human chondrocytes embedded in alginate matrix

Connect Tissue Res. 2011;52(6):503-11. doi: 10.3109/03008207.2011.593673. Epub 2011 Jul 25.

Abstract

Healing capacity of cartilage is low. Thus, cartilage defects do not regenerate as hyaline but mostly as fibrous cartilage which is a major drawback since this tissue is not well adapted to the mechanical loading within the joint. During in vitro cultivation in monolayers, chondrocytes proliferate and de-differentiate to fibroblasts. In three-dimensional cell cultures, de-differentiated chondrocytes could re-differentiate toward the chondrogenic lineage and re-express the chondrogenic phenotype. The objective of this study was to characterize the mesenchymal stem cell (MSC) potential of human chondrocytes isolated from articular cartilage. Furthermore, the differentiation capacity of human chondrocytes in three-dimensional cell cultures was analyzed to target differentiation direction into hyaline cartilage. After isolation and cultivation of chondrogenic cells, the expression of the MSC-associated markers: cluster of differentiation (CD)166, CD44, CD105, and CD29 was performed by flow cytometry. The differentiation capacity of human chondrocytes was analyzed in alginate matrix cultured in Dulbecco?s modified eagle medium with (chondrogenic stimulation) and without (control) chondrogenic growth factors. Additionally, the expression of collagen type II, aggrecan, and glycosaminoglycans was determined. Cultivated chondrocytes showed an enhanced expression of the MSC-associated markers with increasing passages. After chondrogenic stimulation in alginate matrix, the chondrocytes revealed a significant increase of cell number compared with unstimulated cells. Further, a higher synthesis rate of glycosaminoglycans and a positive collagen type II and aggrecan immunostaining was detected in stimulated alginate beads. Human chondrocytes showed plasticity whilst cells were encapsulated in alginate and stimulated by growth factors. Stimulated cells demonstrated characteristics of chondrogenic re-differentiation due to collagen type II and aggrecan synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / pharmacology*
  • Antigens, CD / metabolism
  • Biomarkers / metabolism
  • Cell Differentiation / drug effects*
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Chondrocytes / drug effects*
  • Chondrocytes / pathology*
  • Collagen Type II / metabolism
  • DNA / metabolism
  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism*
  • Glycosaminoglycans / metabolism
  • Humans
  • Hypertrophy
  • Immunohistochemistry
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism

Substances

  • Alginates
  • Antigens, CD
  • Biomarkers
  • Collagen Type II
  • Glycosaminoglycans
  • A73025
  • DNA